They might not have found it yet. You can try picking up your Petpetpets and setting them next to the food. Keep in mind that Petpetpets have their own personalities and only eat when they feel like it.

Resources include wood, water, soil, and grass. Your Petpetpets harvest resources and then use them to maintain and improve your structures. Check the Resources bar at the top right to see what you've collected.

Even when the game is not running on your computer, the Petpetpets still go about their routine. However, they move at a much slower pace. This means that the next time you log in, there will be small changes here and there.